A major focus of crop plant breeders over the last fifty years has been the modification of traits that affect seed composition. Of particular interest to plant breeders have been traits that affect the energy reserves of the seed, including protein and starch. The efforts of plant breeders have led to the development and introduction of crop plants with modified levels and characteristics of these traits.
While mankind has derived many benefits from the past efforts of plant breeders, the combination of the rapidly increasing human population and the decline in land available for agriculture places a tremendous burden on agriculturists to increase both agricultural output and productivity. New and improved crop plant varieties are desired by agriculturists to help meet the challenge of feeding the world's human population. Although traditional plant breeding approaches for crop plant improvement have been successful, the traditional approaches are slow and limited to naturally occurring genetic variation or artificially induced mutations. To keep pace with the escalating demands that the increase in the world's population places on agriculture, more rapid approaches for developing crop plants are necessary. The recombinant-DNA-based methodologies of genetic engineering have already been used successfully to incorporate new insect-resistance and herbicide-tolerance traits into crop plants. Such methodologies have great potential for modifying other characteristics of crop plants including the starch and protein in seeds.